This invention relates to winding electric motor armatures, and particularly to connecting armature coil leads to commutator slots.
The process of manufacturing an electric motor armature involves several wire winding steps, including coiling wire around the armature core and connecting the coil leads to commutator tangs or slots. Although it is often acceptable to terminate the leads using commutators having tangs, it is sometimes necessary, for instance when using heavy-gauge wire, to use commutators that employ slot-type terminations. After each armature core slot is wound, the leads are secured in corresponding commutator slots. When the armature has been completely wound, the wire in the commutator slots is subjected to a fusing operation, which vaporizes the insulation from the wire and creates a mechanically and electrically stable connection between the wire and the slot.
Prior to fusing, the leads may be secured by using commutator slots that are narrower than the wire diameter, which allows the leads to be press-fit into the slots. Alternatively, lead connections may be formed with commutators that have larger slots. In order to hold a lead in a slot of the larger type, a peening tool is used to deform a portion of the center of the slot sidewalls onto the top of the wire. In either case, following initial insertion the wire is looped back on top of itself and further secured.
One drawback of previously known winding machines is that they have incorporated dedicated mechanisms to perform the additional steps associated with forming the wire loop, compacting and securing the wire. These mechanisms have tended to add significantly to the complexity of such systems, slowing their operation and reducing throughput.